This invention relates to general construction. More particularly, this invention relates to an improved system for the erection and stripping of concrete forms in building construction. Still more particularly, this invention relates to a form support structure utilizable in conjunction with the structural members for use in construction systems.
In the art of building construction, a number of methods and apparatuses are known for constructing concrete floors, decks, or ceilings in low-rise or high-rise buildings. It is an aim in these arts to fabricate and ship materials and forms for such construction at comparatively low costs and to reuse the forms readily and simply in erected framework. In such construction, the frameworks and forms previously utilized have varied from relatively simple to quite complex. In general, each particular building project requires an independent determination of the forms, framework, and structural elements which must be employed. However, it is in the interest of the builder and the consumer to utilize forms or adaptable forms capable of readily being erected at the building site and reused. An excellant example of an available forming structure which has been adapted for forming concrete is conventional plywood sheets.
In a certain building construction, in which the flooring slabs in the building construction are integrated with the structural supporting network to provide the required structural strength, a plurality of girders is used to form a structural grid work with a plurality of structural beams or joists. The girders and beams or joists are securely connected to become part of the building structure and are installed at the building site with the use of standard structural units.
In connection with such structural gridwork of girders and beams or joists, plywood of standard dimensions, suitably suspended between the beams and joists, has proved satisfactory in providing a form for the pouring of concrete to form slabs integrated with the girder and joist construction. In such arrangements, it is a continuing problem to provide means for suspending the plywood formwork for its intended purpose while yet being readily removable. Thus, a number of methods directed to a solution of this problem have been devised. For example, the U.S. Pat. No. to Dragunas, No. 3,121,933, describes the use of supporting clips secured to the top flanges of the beam members so that the plywood panels may be placed between the flanges of the beam members and conveniently rest upon the projections provided by the secured clips. After the concrete of the floor slabs above the beam members and the plywood panels has hardened, the clips are fractured and the plywood forms are removed. After being removed, the plywood forms may be reused.
The patent to Klausner, No. 3,307,304, is another example of a frangible clip arrangement for installing and holding concrete forms relative to steel beams and open-web steel joists preparatory to the pouring of concrete so that such forms are easily stripped from the beams and joists following the curing of the concrete.
However, among the difficulties with the use of frangible clip-type members supporting the form is that a plurality of clip sizes is required, and that the clip-type structural elements are not reusable. Accordingly, it is a principal object of this invention to provide a readily-adjustable, strong form support member that can be reused many times. Such form support members are readily adjustable to be used in installations where the spacing between the supporting beams or joists is irregular or in separate installations having differing beams or joists spacing. It is another constraint on the development of such a support member that it be readily positioned for use and securely and safely retained in position during use. In addition, such forms must be readily removed from the installation after the concrete has cured.
Moreover, it is desired to support the concrete plywood form continuously across its full width to reduce its deflection and also to eliminate the possibility of forms slipping off their bearings as could occur where clips are used.
It is prime objective of this invention to provide a reusable form support member capable of being adjustably mounted between beams or joists in building constructions.
It is an additional object of this invention to provide a form support member of the type described which is capable of being readily secured and released from the construction system.
It is yet another object of this invention to provide a form support member having interchangeable telescoping parts.
It is still an additional object of this invention to provide a form support member of the type which provides axially-opposed extensible pin members to be received in beams or joists in a structural configuration to provide support for a concrete form.
It is an additional object of this invention to provide a form support member of the type generally described which is longitudinally adjustable so that the form support member may be utilized in various geometrical configurations and between beams or joists at varied distances.
It is a further object of this invention to provide a form support member of the type which provides axially-opposed, laterally adjustable pin members.
These and other objects and purposes of this invention will become apparent from a detailed description of the invention followinng hereafter, taken in conjunction with the accompanying drawings.